The present invention relates to a process for detecting and assaying a biological substance by erythroadsorption.
Many biological techniques exist for the localization, detection and assay of biological substances. Mention may be made, for example, of immunoenzymatic techniques (immunoenzymatic assays or histochemical detection), immunofluorescence (immunofluormetrical assay or histochemical detection), the radioimmunologic process, the hemagglutination technique and the like.
As reagents, these techniques make use of substances labelled with an enzyme, a fluorochrome or a radioisotope or sensitized red blood cells.
The hemagglutination technique for antibody determination consists in mixing erythrocytes (red blood cells) sensitized by an antigen with a solution containing the antibody to be determined or assayed. This technique is effected in liquid phase. For fuller details about the technique of hemagglutination, reference may be made to the following work, cited as a reference: "Handbook of experimental immunology", 3 vol., Ed. D. M. WEIR, (1978) Blackwell Scientific.
As references illustrating the use of sensitized erythrocytes in processes for the detection or the assay of antigens or antibodies the following references may be mentioned.
German patent application No. 2,732,554 relates to an indicator system for antibody-antigen reactions presented in the form of a gel matrix. This system consists of erythrocytes to which are coupled antibodies or antigens in the presence of a specific buffer and a complement. This system therefore involves erythrocytes sensitized with an antibody or an antigen.
U.S. Pat. No. 4,130,634 relates to a process for detecting the presence of a particular antigen in a composition. This process consists in contacting compositions with erythrocytes to which are coupled specific antibodies of said antigen, in adding a development agent comprising an antibody reacting with said antigen, in adding the complement and in noting the lysis of said erythrocytes as a positive indication of the presence of said antigen.
The the summary of Chemical Abstracts vol. 81, No. 11 of the Sept. 16, 1974, relates to an assay on plates by local hemolysis with sheep erythrocytes sensitized by antigens.
It will be also noted that it was suggested to submit the erythrocytes to a preliminary treatment with one or more tanning agents prior to sensitization. In this connection, reference may be made to French Pat. No. 1,516,640.